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Sessile serrated adenoma seen under microscopy with H&E stain. Serrated polyposis syndrome often does not cause symptoms. The risk of colon cancer is between 25 and 40%. [8] Sessile serrated polyps, as seen during endoscopy or colonoscopy, are flat (rather than raised) and are easily overlooked.
A sessile serrated lesion (SSL) is a premalignant flat (or sessile) lesion of the colon, predominantly seen in the cecum and ascending colon. SSLs are thought to lead to colorectal cancer through the (alternate) serrated pathway. [1] [2] This differs from most colorectal cancer, which arises from mutations starting with inactivation of the APC ...
Adenomatous polyp colon with malignant focus at apex. A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. [1] Untreated colorectal polyps can develop into colorectal cancer. [2] Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) or cause (e.g. as a consequence of ...
The risks of progression to colorectal cancer increase if the polyp is larger than 1 cm and contains a higher percentage of villous component. Also, the shape of the polyps is related to the risk of progression into carcinoma. Polyps that are pedunculated (with a stalk) are usually less dangerous than sessile polyps (flat polyps). Sessile ...
The pathophysiology of precancerous lesions is thought to be similar to that of cancer, and also varies depending on the disease site and type of lesion. [12] It is thought that cancer is always preceded by a clinically silent premalignant phase during which many oncogenic genetic and epigenetic alterations accumulate before it is truly malignant.
These adenomas may become malignant . Villous adenomas have been demonstrated to contain malignant portions in about 15–25% of cases, approaching 40% in those over 4 cm in diameter. [7] Colonic resection may be required for large lesions. These can also lead to secretory diarrhea with large volume liquid stools with few formed elements.
Adenomatous polyps may be classified based on morphology in order to identify lesions at increased risk of malignant transformation. For example, adenomatous polyps in the colon may be pedunculated (lobular head with a long slender stalk) or sessile (broad base).
The countless polyps in the colon predispose to the development of colon cancer; if the colon is not removed, the chance of colon cancer is considered to be very significant. Polyps may also grow in the stomach, duodenum, spleen, kidneys, liver, mesentery, and small bowel. In a small number of cases, polyps have also appeared in the cerebellum.